This relates in general to improvements in printing presses, and more particularly, to an attachment designed to provide a double-feed envelope guide system.
In printing establishments, it is important to provide flexibility for the equipment, which enables the equipment to handle either large or small quantities of materials of different sizes to be printed, with equal facility. Of special concern are devices for printing envelopes, such as the commonly used A. B. Dick Offset printing device, which should be adaptable to the printing of envelopes in different sizes, and different quantities. It is imperative that attachments for converting the offset printing press from single to double-feed status should have a minimal number of parts and should be of such a nature that they can be simply and easily installed and detached without making any significant changes in the basic machine.
A number of prior art devices have been developed which purport to perform the function of converting an offset printing press, such as the type manufactured and sold by the A. B. Dick Company, from single to double-feed status, so as to guide a pair of envelopes side-by-side through the machine simultaneously in perfect register. These devices have been found to be unsatisfactory for one or more of the following reasons:
(a) They require a large number of parts. PA1 (b) They require modification of the primary press by drilling or machining for installation. PA1 (c) They are time consuming to install and disconnect from the primary offset press. PA1 (d) They include parts which require constant adjustment during the period of operation. PA1 (a) it requires no drilling, or other alteration or modification, of the primary duplicating machine for installation of the attachment; PA1 (b) the attachment is simple to install, and comprises a minimal number of parts; PA1 (c) the attachment requires no manual adjustment during operation.
It is therefore the primary object of this invention to provide an improved attachment for guiding two envelopes side-by-side through an offset printing device.
A more particular object of the invention is to provide such an attachment for simultaneously guiding two envelopes through an offset printing device which is simpler and easier to install on an offset duplicating machine than prior art devices for performing a similar function.
Another object of the invention is to provide such a device which comprises a minimum number of parts.
Another object is to provide such a device which is readily installed without drilling or machining to modify the primary press.
Another object is to provide such a device which, after installation, operates successfully to perform its function without manual adjustment or intervention.
These and other objects, features and advantages are realized in an attachment of the present invention for converting a conventional A. B. Dick Offset duplicator to simultaneously guide two envelopes side-by-side through the machine in perfect registration, cutting the actual impressions and running time in half, and requiring no modification of the primary press.